#!/bin/bash
#========================================================================
# Author: YSLin
# Email: 
# File Name: syntax.sh
# Description: 
#   The invocation syntax for awk and sed is as follows:
# 		command 'script' filenames
#   Here command is either awk or sed, script is a list of commands understood by awk or sed, and
#   filenames is a list of files that the command acts on
#	 .		   Matches any single character except a newline.
#	 *		   Matches zero or more occurrences of the character immediately preceding it.
#	 [chars]   Matches any one of the characters given in chars, where chars is a sequence of characters.
#	           You can use the - character to indicate a range of characters. If the ^ character is the first
#	           character in chars, one occurrence of any character that is not specified by chars is
#	           matched.
#	 ^		   Matches the beginning of a line.
#	 $		   Matches the end of a line.
#	 \		   Treats the character that immediately follows the \ literally. This is used to specify patterns
#	           that contain one of the preceding wildcards.
#
#    Set Description
#		 [a-z] Matches a single lowercase letter
#		 [A-Z] Matches a single uppercase letter
#		 [a-zA-Z] Matches a single letter
#		 [0-9] Matches a single number
#		 [a-zA-Z0-9] Matches a single letter or number
#        [^0-9] Matches letter other than any number
#
#    Some Useful Regular Expressions:
#	 String Type Expression
#		 Blank lines				/^$/
#		 An entire line				/^.*$/
#		 One or more spaces			/ */
#		 HTML (or XML) Tags			/<[^>][^>]*>/
#		 Valid URLs					/[a-zA-Z][a-zA-Z]*:\/\/[a-zA-Z0-9][a-zA-Z0-9\.]*.*/
#		 Formatted dollar amounts	/\$[0-9]*\.[0-9][0-9]/
# Edit History: 
#   2011-01-15    File created.
#========================================================================

